Bug 1433932: Avoid crashing on failing to save a capture. r=nical,kats

MozReview-Commit-ID: ARj9ww2F3gx

gfx/webrender_bindings/src/bindings.rs

@@ -1164,20 +1164,26 @@ pub extern "C" fn wr_api_capture(
     path: *const c_char,
     bits_raw: u32,
 ) {
-    use std::fs::File;
+    use std::fs::{File, create_dir_all};
     use std::io::Write;
 
     let cstr = unsafe { CStr::from_ptr(path) };
     let path = PathBuf::from(&*cstr.to_string_lossy());
-    let revision_path = path.join("wr.txt");
+
+    let _ = create_dir_all(&path);
+    match File::create(path.join("wr.txt")) {
+        Ok(mut file) => {
+            let revision = include_bytes!("../revision.txt");
+            file.write(revision).unwrap();
+        }
+        Err(e) => {
+            println!("Unable to create path '{:?}' for capture: {:?}", path, e);
+            return
+        }
+    }
+
     let bits = CaptureBits::from_bits(bits_raw as _).unwrap();
     dh.api.save_capture(path, bits);
-
-    let revision = include_bytes!("../revision.txt");
-    File::create(revision_path)
-        .unwrap()
-        .write(revision)
-        .unwrap();
 }
 
 #[cfg(target_os = "windows")]